reap: skip synthetic tree nodes (fixes 422 on batch-delete)

dashboard-data.ts synthesizes a few org/company/team placeholders
("my-workspace", "ws-teams", "ungrouped-co", "ungrouped-team") so
an empty workspace still has something to render. Their ids
aren't UUIDs and don't exist in the DB.

Before the cascade-reap change these were unreachable because
selectLevel="claw" restricted the checkbox affordance to leaf
agents. With selectLevel="*" they became selectable, and
POST /api/claws/batch-delete returned 422 (serde couldn't parse
"ws-teams" as a UUID).

Fix: skip synthetic ids in onToggleSelect so they can never enter
selectedAgents in the first place, and filter the request body to
strict UUIDs at send-time as a defense. If the filter empties the
list the modal surfaces a friendly message instead of firing.

frontend/src/components/dashboard/Dashboard.tsx

@@ -53,6 +53,16 @@ const COMPUTER_WIDTH: Record<DeviceSize, string> = { phone: "448px", tablet: "67
 type Tier = "world" | "research" | "loops" | "claw" | "repos" | "infra";
 const mono = "'JetBrains Mono', ui-monospace, monospace";
 
+// dashboard-data.ts fabricates a few org/company/team nodes so an empty
+// workspace still has something to render. These ids aren't UUIDs and
+// don't exist in the DB — treat them as non-selectable for reap.
+const SYNTHETIC_TREE_IDS = new Set([
+  "my-workspace",
+  "ws-teams",
+  "ungrouped-co",
+  "ungrouped-team",
+]);
+
 // Gradient palette for structure nodes that don't carry their own (companies,
 // teams). Agents bring their own grad/ink.
 const NODE_GRADS: [string, string][] = [
@@ -656,7 +666,13 @@ export function Dashboard({ user, orgs, claws }: { user?: { display_name?: strin
           ) : (
             <>
           {/* The collapsible org → company → team → agent tree (World) or the flat agents list. */}
-          <StructureTree roots={treeRoots} activeId={treeActiveId} autoExpand={treeAutoExpand} onSelectNode={onTreeSelect} selectMode={selectMode} selectLevel={"*"} selectedIds={selectedAgents} onToggleSelect={(id) => setSelectedAgents((prev) => { const next = new Set(prev); if (next.has(id)) { next.delete(id); return next; } const lv = nodeLevel.get(id); const curLv = prev.size ? nodeLevel.get([...prev][0]) : lv; if (lv !== curLv) return new Set([id]); next.add(id); return next; })} />
+          <StructureTree roots={treeRoots} activeId={treeActiveId} autoExpand={treeAutoExpand} onSelectNode={onTreeSelect} selectMode={selectMode} selectLevel={"*"} selectedIds={selectedAgents} onToggleSelect={(id) => {
+            // Synthetic UI-only containers ("my-workspace", "ws-teams",
+            // "ungrouped-co", "ungrouped-team") aren't real DB rows — the
+            // backend would 422 on the non-UUID id. Silently ignore taps.
+            if (SYNTHETIC_TREE_IDS.has(id)) return;
+            setSelectedAgents((prev) => { const next = new Set(prev); if (next.has(id)) { next.delete(id); return next; } const lv = nodeLevel.get(id); const curLv = prev.size ? nodeLevel.get([...prev][0]) : lv; if (lv !== curLv) return new Set([id]); next.add(id); return next; });
+          }} />
           {selectMode ? (
             <div style={{ flex: "none", borderTop: "1px solid rgba(255,255,255,.08)", padding: "10px 12px", display: "flex", flexDirection: "column", gap: 8 }}>
               <div style={{ fontFamily: mono, fontSize: 11, color: selectedItems.length ? "#ff8a7a" : "#6a6a72" }}>{selectedItems.length} selected{selectedItems.length ? ` · ${reapKind}` : ""}</div>

frontend/src/components/dashboard/ReapProgressModal.tsx

@@ -45,7 +45,16 @@ export function ReapProgressModal({ items, kind, onClose, onDone }: { items: Ite
         // One SSE stream regardless of kind. The backend expands
         // teams/companies/orgs to the agents inside them, reaps each, then
         // deletes the group rows.
-        const body: Record<string, string[]> = { [BODY_KEY[kind]]: items.map((i) => i.id) };
+        // Filter to real UUIDs — the tree can surface synthetic placeholder
+        // ids ("ws-teams", "ungrouped-co", …) that would 422 on the server.
+        const UUID = /^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$/i;
+        const validIds = items.map((i) => i.id).filter((id) => UUID.test(id));
+        if (validIds.length === 0) {
+          setError("Nothing reap-able selected (synthetic containers can't be deleted).");
+          setFinished(true);
+          return;
+        }
+        const body: Record<string, string[]> = { [BODY_KEY[kind]]: validIds };
         const res = await fetch("/api/claws/batch-delete", { method: "POST", headers: { "Content-Type": "application/json" }, body: JSON.stringify(body) });
         if (!res.ok || !res.body) { setError(`Request failed (${res.status})`); setFinished(true); return; }
         const reader = res.body.getReader();